1. Field of the Invention
The present invention relates to check valve assemblies and, more particularly, to a modular fluid casing for a check valve.
2. Description of Related Art
Fluid valves generally include a main body having two ends. The main body also forms an internal flow cavity that fluidly connects the two ends and houses internal valves. In a typical installation, one end of the main body is connected to a fluid inlet pipe and the other end is connected to a fluid outlet pipe. Fluid flows from the fluid inlet pipe, through the internal flow cavity, is stopped, directed, or left unimpeded by the internal valves, and exits through the fluid outlet pipe. Such fluid valves can include backflow prevention valves (i.e., double check and reduced pressure principle valves).
Some fluid valves have movable parts, such as independently acting internal reciprocating check valves, positioned in the internal flow cavity formed by a main body. An inlet shutoff valve, or some other member, as shown in U.S. Pat. Nos. 1,969,432; 3,245,257; 3,946,754; 4,327,760; 5,392,803; 5,511,574; and 5,732,744, is typically positioned adjacent one end of the main body and an outlet shutoff valve is positioned adjacent the other end of the main body. In turn, each shutoff valve is connected, respectively, to the fluid inlet pipe or the fluid outlet pipe. The shutoff valves are required for testing and service of the backflow prevention valve.
The repair, inspection, or replacement of such check valves typically requires the flow of fluid to be shut off at the valve inlet and outlet, thus stopping the flow of fluid through the pipe. Access to internal components of such check valves are typically accomplished through one or more access ports or openings. Under certain regulatory codes, the main body which houses the fluid valves cannot be completely removed from the fluid handling system during routine maintenance and inspection of the valves. Therefore, maintenance and inspection of such valves can become difficult when the main body is in a location that is not easily accessible to maintenance personnel.
In some fluid handling installations, a bypass line is often used to maintain fluid flow through the system while the other fluid valves are either being repaired or replaced. This bypass line adds additional costs and takes up extra space in the fluid handling installation. In some installations, a minor disruption in the fluid flow may not result in serious adverse consequences downline of the fluid handling installation. Therefore, if the time of repair, replacement, or inspection of a fluid valve can be minimized, the need for an additional bypass line may not be required.
Therefore, it is an object of the present invention to overcome the above-mentioned deficiencies by providing a modular fluid casing for a check valve that provides for easy maintenance and replacement of check valves with minimal disruption of the flow in a fluid handling installation.